Clinical outcomes of scalp or face angiosarcoma treatment with intensity-modulated radiotherapy: a multicenter study

Abstract Background: Combined modality therapy, including radiotherapy (RT), is a common treatment for scalp or face angiosarcoma. Although intensity-modulated radiotherapy (IMRT) can deliver homogeneous doses to the scalp or face, the clinical data are limited. The aim of this multicenter study was to evaluate the scalp or face angiosarcoma treated with definitive or postoperative IMRT. Methods: We retrospectively analyzed data from patients who received IMRT for scalp or face angiosarcoma at three institutions between January 2015 and March 2020. Local control (LC) rate, overall survival (OS), progression-free survival (PFS), recurrence patterns, and toxicity were evaluated. Results: Fifteen patients underwent IMRT during the study period. Definitive RT was performed in five patients and postoperative RT in 10 patients. The 1-year LC rate was 85.7% (95% confidence interval [CI], 53.9–96.2%). The 1-year OS and PFS rates were 66.7% (95% CI, 37.5–84.6%) and 53.3% (95% CI, 26.3%–74.4%), respectively. Univariate analysis revealed that the presence of nodules in the primary tumor and a clinical target volume over 500 cm3 were associated with poor LC. Distant metastasis was the most common recurrence pattern. All patients experienced grade 2 or 3 radiation dermatitis, and five patients experienced ≥ grade 3 skin ulceration. Fisher’s exact test showed that postoperative RT was significantly associated with an increased risk of skin ulceration of grade ≥ 3. Conclusions: IMRT is a feasible and effective treatment for scalp or face angiosarcoma, although skin ulceration of ≥ grade 3 is a common side effect in patients who receive postoperative RT.